Search Results (4)

Pyrolysis is a thermochemical conversion process producing biochar, gas, and bio-oil at high temperatures in an oxygen-free environment. Specific pyrolysis conditions enable a significant production of the aqueous phase of bio-oil, commonly known as wood vinegar. Wood vinegar contains organic compounds such as acetic acid and phenols derived from bio-oil. These compounds have herbicidal properties against weeds and biostimulant properties for plant growth. This study reveals the potential for efficient management of cranberry residues consisting of stems and leaves by producing wood vinegar through pyrolysis at 475 °C with a humidity level of 20%. Membrane separation of wood vinegar, using nanofiltration (NF) and reverse osmosis (RO) membranes, yielded phenols in the retentate and acetic acid in the permeate with respective yields of 44.7% with NF membrane and 45% with RO membrane. Biostimulation tests using 2% of the retentate showed significant germination rates for basil, sage, and parsley plants. Additionally, using 40 mL of the wood vinegar permeate (30 mL injected at the base and 10 mL sprayed on the leaves) resulted in leaf damage, measured by conductivity (leakage of electrolytes released by the leaves), of 62.3% and 20.5% respectively for quack grass and white clover, two weeds found in cranberry production. Full article

This study presents various research methods and results analysis of the total antioxidant status (TAS), polyphenols content (PC) and vitamin C content in selected plant materials (vegetables) subjected to various technological processes, including sous-vide. The analysis included 22 vegetables (cauliflower white rose, romanesco type cauliflower, broccoli, grelo, col cabdell cv. pastoret, col lllombarda cv. pastoret, brussels sprouts, kale cv. crispa–leaves, kale cv. crispa–stem, toscana black cabbage, artichokes, green beans, asparagus, pumpkin, green peas, carrot, root parsley, brown teff, white teff, white cardoon stalks, red cardoon stalks and spinach) from 18 research papers published in 2017 to 2022. The results after processing by various methods such as conventional, steaming and sous-vide cooking were compared to the raw vegetable results. The antioxidant status was mainly determined by the radical DPPH, ABTS and FRAP methods, the polyphenol content by the Folin–Ciocalteu reagent and the vitamin C content using dichlorophenolindophenol and liquid chromatography methods. The study results were very diverse, but in most studies, the cooking techniques contributed to reducing TAS, PC and vitamin C content, with the sous-vide process being most beneficial. However, future studies should focus on vegetables for which discrepancies in the results were noted depending on the author, as well as lack of clarity regarding the analytical methods used, e.g., cauliflower white rose or broccoli. Full article

To develop a cutting, harvesting, crushing or grinding machine, knowledge of the crop’s physical and mechanical properties is needed. In this study, the shear strength, shear energy and maximum shear force in cutting parsley stems is examined. The cutting of multiple stems (eight stems) was performed using blades with oblique angles of 0°, 20° and 40°. In order to examine the effects of the stem arrangement in the cutting operation, the stems were placed in row and bundle arrangements. Statistical analysis showed that the shear strength and maximum shear force decreased with the increasing oblique angle. The average values of the shear strength, specific cutting energy and maximum shear force for cutting eight stems laid in a row arrangement using a blade oblique angle of 0° were 0.49 MPa, 2.25 mJ mm⁻² and 56.13 N, respectively, while at a blade angle of 40°, the values were 0.19 MPa, 4.12 mJ mm⁻² and 18.2 N, respectively. A blade angle of 20°is recommended as it does not require more cutting energy compared to 0°, and the shear force is reduced, which lessens the effect of impacts on the cutting system. Full article

The problem of cleaning and disinfecting surfaces has become extremely important in the context of the ongoing SARS-CoV-2 coronavirus pandemic. However, it should be considered that, in everyday life, we come into contact with many other viruses, as well as pathogenic bacteria and fungi, that may cause infections and diseases. Hence, there is a continuous need to search for new and more effective methods of fighting pathogens. Due to their documented antimicrobial activity, silver nanoparticles may be an interesting alternative to the commonly used surface cleaners and disinfectants. Therefore, the present study aimed to evaluate the bactericidal properties of silver nanoparticles obtained with the use of nontoxic plant waste biomass against bacteria isolated from the environment. Silver nanoparticles with the desired physicochemical characteristics were obtained by a simple and rapid chemical reduction method using plant waste such as unused parsley stems and potato peels (the biogenic method). A nanosilver colloid was also prepared by the chemical reduction method, but with reducing and stabilizing chemical substances (the chemical method) used as a control. The bacterial susceptibility to nanosilver synthesized using both methods was evaluated using the disk-diffusion method. The sensitivity of particular Escherichia coli and Staphylococcus aureus isolates to nanosilver varied considerably, and the strongest antimicrobial effect was found in the case of nanoparticles synthesized by the chemical method using a strong chemical reducing agent and a polymeric stabilizing substance, while nanosilver obtained using the biogenic method, using phytochemicals, also had a strong antimicrobial effect, which was found to be extremely satisfactory. Thus, it can be strongly concluded that the biogenic, pro-ecological method of synthesis with the use of plant waste biomass presented in this work allows the application of biogenic nanosilver as a component of agents for washing and disinfection of public utility surfaces. Full article